Ultimaker 2, don't work exactly right

[danidore 0]

Hei there,

I have some problems but i can't figure out what is wrong with this printer; the thing is it basically works fine but almost always skips steps (the little extrusion engine in the back makes that annoying squeak sound and goes back a little).

I manage to do some excelent prints but with a lot of effort, 5-10 tryouts, and the thing I wish to fix the most is speed; I can only print decent stuff at speeds of 50% or bellow (and it takes a lifetime).

Most problems appears when the resolution is over 150 microns... Bellow that 100 or 60 works a little bit better.

I noticed that ABS is almost impossible to control, especially on bigger objects; I use mostly PLA bought from Ultimaker so the material shouldn't be a problem (I tested other materials and they really suck). To make something acceptable I set the nozzle temperature for PLA at 235-240 degrees so the process of skipping steps won't let gaps in the prints but I don't think is ok...

I'm almost sure that something is wrong with it but I don't know what. Can someone give me some pieces of advice? I can run some tests, I can upload pictures, I can give you the parameters...

[nallath 1,120]

This sounds like under extrusion problem; The teflon part deforms, making it harder to push material through the nozzle. This is why the problem occurs at thicker layers and higher speeds, as it needs to push more mm3 per second.

Replacing the teflon inset should help greatly (Recent machines should have a spare one with it).